If the kids are primary school age and if you an get them into a decent school, I believe expat life, in general, is better for them than UK. (The OP's location is unclear?) More sport, more interaction with other nationalities etc etc and generally less sitting at a computer on rainy days. If they are older, education can be more problematic. Make sure you can get a curriculum/national system that suits.
Your wife could be a 'Jumairah Jane' (does little other than shopping and socialising...) or she could have an active life perhaps working or helping with a charity. Truth is she'll probably spend a lot of time as a 'taxi driver' for the kids or in taxis.
Summer in the Gulf is not funny - most families leave for the duration. But the rest of the year the climate is great.